Biomedical subjects

M N Sarbolouki

Publications and source records attributed to M N Sarbolouki.

7 recordsLinked to original sources

PubMed2006

Decolorization of textile azo dyes by newly isolated halophilic and halotolerant bacteria.

Studies were carried out on the decolorization of textile azo dyes by newly isolated halophilic and halotolerant bacteria. Among the 27 strains of halophilic and halotolerant bacteria isolated from effluents of textile industries, three showed remarkable ability in decolorizing the widely utilized azo dyes. Phenotypic characterization and phylogenetic analysis based on 16S rDNA sequence comparisons indicate that these strains belonged to the genus Halomonas. The three strains were able to decolorize azo dyes in a wide range of NaCl concentration (up to 20%w/v), temperature (25-40 degrees C), and pH (5-11) after 4 days of incubation in static culture. They could decolorize the mixture of dyes as well as pure dyes. These strains also readily grew in and decolorized the high concentrations of dye (5000 ppm) and could tolerate up to 10,000 ppm of the dye. UV-Vis analyses before and after decolorization and the colorless bacterial biomass after decolorization suggested that decolorization was due to biodegradation, rather than inactive surface adsorption. Analytical studies based on HPLC showed that the principal decolorization was reduction of the azo bond, followed by cleavage of the reduced bond.

Biodegradation, Environmental↗

PubMed2006

Aerobic decolorization and detoxification of a disperse dye in textile effluent by a new isolate of Bacillus sp.

A number of aerobic species capable of decolorizing some of the dyes in a textile mill effluent were isolated. One of the isolates was able to decolorize Terasil black dye under aerobic conditions in the presence of an exogenous carbon source after 5 days. Glucose or starch (%1 ea) are essential for decolorization but the process proceeds faster in the presence of 0.5% yeast extract. Results of the BOD(5) show that the untreated effluent samples have a low BOD value, whereas treated samples show an initial increase in BOD up to 15 days followed by a decrease after 20 days. FT-IR and GC-MS data also reveal that the initial components in the untreated effluent disappear after 20 days of treatment, confirming biodegradation of the dye. Phytotoxicity tests on the untreated effluent samples using the seeds of Lens orientalis, Triticum aestivum, and Triticum boeoticum indicate that the first one is the most sensitive while the last one is the most resistant. On the other hand the treated effluent allows 90% germination in Triticum boeoticum seeds and 100% germination in the other two.

Azo Compounds↗

PubMed2001

A simple method for preparation of immuno-magnetic liposomes.

A simple and readily manoeuverable method for preparing immuno-magnetic liposomes that indigenously contain binding sites for attaching other molecules like antibodies on their exterior surface is described. In this method magnetic unilamellar vesicles are prepared from a mixture of phosphatidylcholine, cholesterol, small amounts of a linear chain aldehyde and colloidal particles of magnetic iron oxide, using a reverse phase evaporation technique. The aldehyde (dedecanal) molecules align themselves among the lipid molecules in the bilayer with their aldehyde groups exposed to the aqueous phase, allowing straight attachment of antibody molecules (human-antimouse IgG-FITC in this case) in one single step. The success of this approach is confirmed by fluorescence microscopy as well as binding of the resulting immuno-magnetic liposomes to their corresponding target cells.

Aldehydes↗

PubMed2000

A novel human tocopherol-associated protein: cloning, in vitro expression, and characterization.

Vitamin E (alpha-tocopherol) is an essential dietary nutrient for humans and animals. The mechanisms involved in cellular regulation as well as in the preferential cellular and tissue accumulation of alpha-tocopherol are not yet well established. We previously reported (Stocker, A., Zimmer, S., Spycher, S. E., and Azzi, A. (1999) IUBMB Life 48, 49-55) the identification of a novel 46-kDa tocopherol-associated protein (TAP) in the cytosol of bovine liver. Here, we describe the identification, the molecular cloning into Escherichia coli, and the in vitro expression of the human homologue of bovine TAP, hTAP. This protein appears to belong to a family of hydrophobic ligand binding proteins, which have the CRAL (cis-retinal binding motif) sequence in common. By using a biotinylated alpha-tocopherol derivative and the IASys resonant mirror biosensor, the purified recombinant protein was shown to bind tocopherol at a specific binding site with K(d) 4.6 x 10(-7) m. Northern analyses showed that hTAP mRNA has a size of approximately 2800 base pairs and is ubiquitously expressed. The highest amounts of hTAP message are found in liver, brain, and prostate. In conclusion, hTAP has sequence homology to proteins containing the CRAL_TRIO structural motif. TAP binds to alpha-tocopherol and biotinylated tocopherol, suggesting the existence of a hydrophobic pocket, possibly analogous to that of SEC14.

Amino Acid Motifs↗

PubMed1975

Pore flow models and their applicability.

Pore flow models are classified and concisely reviewed, and it is shown that despite their apparent differences, they are equivalent. It is proven that the difference between the classic formula of Guerout-Elford-Ferry and the most recent ones developed by Pappenheimer-Ussing and Kedem-Katchalsky, is due to the introduction of a more proper viscosity coefficient for the water inside the membranes in the newer formulae. Fundamental assumptions involved in the models are restated and criteria for their applicability are mentioned. Arguments regarding the fundamental validity of the pore size formulae when applied to tight membranes, where continum hydrodynamics become questionable, are reviewed. Recent theoretical analysis of the situtation by Mikulecky, where he shows the calculated pore size merely reflects the extent of the membrane-water interaction is briefly presented. It is argued that since his analysis neglects the influence of the membrane-water interaction on the viscosity coefficient, his treatment is far from conclusive. In support of this argument, the results of the Kinetic studies of Levitt based on direct simulation through molecular dynamics is presented where water molecules (considered as non-interacting hard spheres of 1A radius) are observed in a rigid cylindrical pores of 3.2A in radius and 11A long. The pore size, calculated following the procedures of pore flow models, is in good agreement with the physical size of the simulated pore. It is then concluded that the fundamental validity of the pore flow models in the case of tight membranes is yet unsettled, theoretically, but empirically its validity seems confirmed in some instances.

Mathematics↗

PubMedDate not supplied

Mixed micelle proliposomes for preparation of liposomes containing amphotericin B, in-vitro and ex-vivo studies.

The aim of this work was to produce a form of injectable liposomes containing amphotericin B derived from mixed micelle proliposomes. Mixed micelles were derived from a mixture of lecithin/sodium cholate in aqueous media. The solubility of amphotericin B in proliposomes was studied as a function of lipid composition (total lipid concentration, molar ratio of lecithin/sodium cholate), and the dispersion media (pH, ionic strength, presence or absence of human serum albumin), and the temperature. The data show that micelle-->liposome transformation occurs during the dilution of proliposomes containing amphotericin B. These transformations could be followed via transmission electron microscopy (TEM). Data related to dilution of proliposomes as well, show that under no circumstance there occurs any precipitation that might be assigned to the decreased solubility of amphotericin B. These indicate that the incorporated drug also participates during the transformation of the proliposomes into liposomes. It is thus concluded that mixed micelle proliposomes are prime candidates for the production of a form of injectable amphotericin B in liposomes.

Amphotericin B↗

PubMedDate not supplied

Storage stability of stabilized MLV and REV liposomes containing sodium methotrexate (aqueous & lyophilized).

Multilamellar and unilamellar liposomes containing sodium methotrexate (MTX) were prepared by thin film hydration and reverse-phase evaporation methods. Encapsulation efficiency and release of MTX from liposomes at 4 degrees C, 25 degrees C and 37 degrees C were determined. When stored at 25 degrees C the liposomes lost 33% MTX after one month. To stabilize liposomes, they were freeze-dried in presence of different amounts of cryoprotectants (trehalose, PEG 10,000, PEG 20,000, and a mixture of trehalose-PEG 20,000). Measurements showed that the mixture of trehalose-PEG 20,000 imparted an MTX retention of about 70% after lyophilization. Stability tests of the lyophilized product at 4 degrees C, 25 degrees C and 37 degrees C demonstrated they were fairly stable even at 37 degrees C, indicating their potential use in commercial applications.

Drug Carriers↗